Road Test of the Land Rover Discovery TD5

The 1999 Discovery is a surprise in many ways.
At first glance it doesn't look as if
Land Rover has changed a thing on the new model.
LR stated at the release of the new Disco'
that customer service had found that owners would like the Discovery
to keep its existing appearance.
So the new model looks very much like the old.
That is just about the end of any similarities however
as many other things have changed and the biggest surprises are in
the technological side of the vehicle.
The case is that the vehicle is so advanced that many of
the sales people won't have a clue how some of the new systems work.
Hopefully the merits of the systems will sell themselves.

The Td5 engine is a new engine for Rover/BMW.
The previous Tdi engine's ancestry goes back to the 1950's.
The new five cylinder turbo charged diesel engine is
way ahead of the old engine.
Power is up over the old engine's 83 @ 4000r;
the Td5 produces 101.5 @ 4200 r and
the new torque figure for the manual vehicle is 300 @ 1950 r.
(The old Tdi produces 265 @ 1800r.)
Other features of the new engine include a newly developed direct
injection systems that allows the engine to run so clean
that it passes post year 2000 emission tests without a
catalytic converter and an advanced oil filtration system that allows
service intervals to be increased to 12000 miles.

The 5 speed manual is an updated version of the previous model's
gearbox however the transfer box is very different and compared
to traditional four wheel drive systems is a complete spin out
for those interested in technology.
High and low ratio work in the normal way however the centre differential lock
is no longer in use and no viscous coupling is fitted
to do the work of sending the power equally to each end of the vehicle.
Instead,
the four wheel drive system is controlled by an advanced
four wheel Electronic Traction Control system known as ETC.
The system works through the brake's ABS system and
monitors the behaviour of each wheel and the (electronic) throttle.
If one wheel spins or locks, the traction control adjusts the brakes
accordingly.
Hence if only one wheel has traction, the system maintains drive to that wheel.
Another aspect related to the ETC is the Hill Decent Control or HDC.
This allows, when the vehicle is in low ratio,
for the descent speed of the vehicle to
range between 7 and 14 km/h depending on the gear used.
This system may be of great use in a petrol automatic vehicle
where engine braking is not adequate, but for a diesel manual
it seems rather pointless as engine braking is so good.
The brake system also has Electronic Brake Distribution or EDC.
This system distributes the brake bias so that
the corner that needs it, gets it.

Suspension

Suspension is the next part that was given a
tough going over by the design department.
The previous model, even with the addition of anti-sway
bars, gave a lot of body roll.
To combat this Land Rover have made a huge step forward
by offering an active
suspension
system on the new model.
This is known as is Active Cornering Enhancement, or ACE.
The body is fitted with two accelerometers that measure the G-forces
on the vehicle.
The anti-sway bars are fitted with two hydraulic
rams which are adjusted in relation to the G-forces
due to cornering, thus limiting body-roll on fast corners to normal
car levels.
Off road, the vehicle detects roll with
other sensors and adjusts the hydraulic rams at low speeds
to allow for full axle articulation.
The front axle has coil springs where the rear has
adjustable air springs that give the vehicle self leveling suspension or SLS;
this can detect if the vehicle is heavily loaded or if a trailer is fitted.
A height level can be selected with a
switch on the dash, giving 40mm more ground clearance.
This self cancels above 30 km/h.
The electronics can even tell if the back-end is dragging off-road and
automatically raise it for you.

Body

Although the body work looks almost identical
to the previous model, at first glance, many changes and
updates have been incorporated. The track of the vehicle is wider
than before which gives it a much stronger look,
especially with the optional 18" alloy wheels. The rear lights
are the most noticeable change being placed high on the rear
pillars. The new door handles make a difference as the old style
ones dated back to the Morris Marina! The windscreen is
larger and the panel gaps have been improved as has
the sealing to keep out dust and water.

The interior looks almost the same as before.
The most notable change is in the rear seats.
They are now facing forward for safety reasons.
This has caused an increase in the body length behind the rear axle of 150 mm.
The chassis has been strengthened with more cross members to improve
the overall rigidity of the vehicle.

On Road

Overall on paper you have a vastly improved Discovery over the old model
which still has all the features that where fine.
How all this new technology works on the road is interesting.
The previous model Discovery is a very comfortable vehicle and
jumping into the new model is as though you were in either model.
Just give the inner handle two pulls.
The first raises the button for you and the second opens the door.
That is were it stops.
Fire up the Td5 and its quietness and lack of diesel clatter is
instantly noticeable.
The engine revs very freely and feels comparatively effortless where as
the Tdi always had you working harder to get the best out the engine.
The smoothness of the engine is another aspect that is instantly noticed.
Its easy to use the rev range of the new engine as well as it revs so easily.
Dropping down gears to get a bit more legs
is easy where you had to rely more on the torque of the Tdi.
The sound proofing is very improved as you can't hear
the turbo charger where as its whistle was always there on the Tdi.
One thing that was noticed was the electronic throttle.
It wasn't a problem at all but just felt different perhaps due
to the weighting of it.

The suspension is very car-like and doesn't feel
at all like the old vehicle, and as the body-roll controls are automatic
it is a case of out of sight and out of mind.
You can go around hard corners and not know that you are in a 4WD.

Off Road

The chance to take it off road was to be the most interesting
part of the day -- to see how all this electronic trickery works.
Our test vehicle was shod with the 18" alloys and road-based Goodyears.
It had been snowing the day before in
the hills just out of Melbourne which was great as all the
tracks were very greasy.
We came to our test slope that was about 30 degrees at
it worst, well used and rutted at the
bottom climbing to a telephone tower:
Select low ratio and go.
The bottom was very slippery but the Td5 just walked
over it as though it wasn't there.
We stopped and did a restart on the steepest section of the track and once
again, no problem.
I was trying to imagine how far this thing would go if you put
off road tyres or even wheel chains on it.
Very impressive as it made the climb so easy.
On the way down we selected the hill decent control and went for it.
Even if you take the vehicle out of gear the hill decent control
still keeps you creeping along.
Quite incredible.
The other great aspect of all this is that tract erosion
and damage will be completely minimised with these systems.

One minor feature I liked was that if you lock your door from the
inside you don't have to pull the button up
and grab the inner door handle.
With regard to space,
the rear area is noticeably larger than in the old model making luggage
packing a breeze; the extra room makes life
that bit more comfortable when packing luggage.

Overall

The technology is great, unbelievable, a fantastic vehicle.
I would highly recommend a test drive, especially off road,
as it is very capable and makes the previous Discovery
look like a bit of a pretend four wheel drive.
It would be almost unstoppable with wheel chains fitted.
It will be interesting to see durable the hi-tech features are
in long-term service.
Thinking back to 1989 when the Discovery was first released,
who would have thought that
in ten years its four wheel drive systems and suspension would
have become this elaborate?
The new diesel engine is excellent in its refinement and power, and
it is environmentally friendly as well.
It is easy to say that Land Rover could have gone further
with the body work in releasing a newer shape to go with the new
under-pinnings.

Going by what it has shown it can do,
no doubt Land Rover has even more in mind for the future.